Protein conjugates made with Alexa Fluor® dyes produce fluorescence output that surpasses that of other spectrally similar fluorophore-labeled proteins. Alexa Fluor® dyes are available in a wide selection of fluorescent colors and are more photostable than most other dyes.

Unsurpassed Brightness

Alexa Fluor® dye molecules can be attached to proteins without significant self-quenching, leading to brighter conjugates. Whether it is Alexa Fluor® 488 (Figure 1), Alexa Fluor® 555 (Figure 2), or Alexa Fluor® 647 (Figure 3), or any other Alexa Fluor® dye, you will get the brightest conjugate available for imaging, flow cytometry, and other fluorescence-based applications.

Figure 1. Comparison of relative fluorescence of goat anti–mouse IgG antibody conjugates prepared from the Alexa Fluor® 488 dye and fluorescein isothiocyanate (FITC). Conjugate fluorescence is measured by comparing the fluorescence quantum yield of the conjugated dye relative to that of a reference dye and multiplying by the dye:protein labeling ratio.

Figure 2. Comparison of relative fluorescence of goat anti–rabbit IgG antibody conjugates of the Alexa Fluor® 555 and Cy®3 dyes (prepared by Invitrogen) at different dye:protein ratios in the conjugate.

Use Antifade Reagents for Improved Signal Stability

Whether using Alexa Fluor® dyes or other standard dyes, you can suppress photobleaching and preserve signal brightness by using Prolong® Gold Antifade. Compatible with a multitude of dyes across the spectrum, this is a valuable tool for multicolor applications.